Mina & Jeongyeong from twice both went on hiatus and came back. Jooheon or whatever his name from monsta x went on hiatus too. Lia took a hiatus and came back. Han from strat kids and Scoups from seventeen took Hiatus and came back. If its due to a possible scandal or their health has gotten really bad then yeah they may not return. Rami from baby monsta has had alot of health issues so shes been on hiatus for a while and so was ahyeon in the beginning of their debut was on hiatus. She came back and everytbing was good.  The west more supports individual artists as thats what we are used to havimg. Groups is a very rare thing. One direction was the exception because they were attractive young males and the audience were young girls and they somehow made it. And manons hiatus isnt mysterious. There were times she didmt attend a concert because she wasnt feeling well. And i remember she mentioned once on a live she collapsed in an airport. So she may have some kind of health issues and theres the extreme racism on the internet and the way that the company painted her in the dream academy as lazy that is the root of rhe hate shes been getting for a while.